Close coupled truck



Dec. l, 1953 H. J. FRAMHEIN CLOSE COUPLED TRUCK 3 Sheets-Sheet 1 Filed April 7, 1951 lNVENTOR ATTO R N EY Decl953 H. J. FRAMHEIN cLosE couPLED TRUCK 3 Sheets-Sheet 5 Filed April 7, 1951 INVENTOR HiT/@ M e ATTO R N EY Patented Dec. 1, 1953 UNITED STATES ATENT OFFICE CLOSE COUPLED TRUCK Application April 7, 1951, Serial No. 219,7 84

6 Claims.

This invention relates to industrial trucks of the class having an elevating platform upon which the load is carried, and in which the platform is supported for lifting movement at its front end on a lifting head and at its rear end upon suitable wheeled lifting means that serve as the rear wheels of the truck. More particularly, my invention relates to improvements in the mechanism whereby the elevating platform in such trucks is connected with and moved relatively to the lifting head.

It has been customary to provide the elevating platform and the lifting head in trucks of this general class with standards to accommodate the connecting mechanism, one example of such a construction being disclosed in my prior patent, No. 2,519,128 dated August 15, 1950, and entitled Lift Truck. The standards there provided have contributed materially to the length of the truck, and this is particularly true because the connecting mechanism involved swinging links. The utilization of a vertical rectilinear mounting in my prior patent is not possible except through a wide spacing between the vertical standards of the truck.

I have now provided a novel truck of the class described in which the standards and the lifting and connecting mechanisms occupy less space longitudinally of the truck than has been possible previously, thereby permitting the truck to be made shorter and more maneuverable without any sacrifice in its load handling capacity.

As one feature of the invention, I construct the connecting mechanism in such a way that the lifting and lowering movements of the elevating platform will occur in a straight line relatively to the lifting head. This straight line movement of the platform permits one of the standards to be arranged compactly within the other, since the only relative movement between the standards is longitudinally thereof, The connection between the standards preferably is effected by a track and follower means which may take the form of channel members in one standard engaged by rollers on the other standard. The movement of the elevating platform relatively to the lifting head operates the lifting means for the rear end of the platform through a cam on the lifting head, and because the movement of the platform is rectilinear, the effect of the cam will be proportional to the movement of the elevating platform.

As a further part of this feature of the invention, any necessity for a cross-connection to asis inherent in the track and follower means that forms a part of my invention.

As another feature of my construction, the as'- sembly of the truck is facilitated through the particular arrangement whereby the elevating platform moves relatively to the lifting head. Thus, these parts may be assembled by sliding one of the standards into the other in such a way that the rollers on one standard enter the channels in the other standard, and this operation may be acl complished without the necessity for carefully aligning and positioning the parts as is the case when swinging links connect the lifting head to the platfrom.

Another feature of the invention resides in the construction whereby the front end of the elevating platform is lifted by a force that is applied always in a direction alignedr with the movement of the platform. This is accomplished in the preferred form of the invention by mounting the lifting ram within the standards in a position parallel to the track and follower means, and not only results in a very compact arrangement, but also minimizes stresses and wear on the parts.

I have thus outlined rather broadly certain features of my invention in order that the detailed description thereof that follows may be Vbetter understood, and in order that my contributionv to the art may be better appreciated. There are, of course, additional features of my invention that will be described hereinafter, and which will form the subject of the claims appendedhereto.

Those skilled in the art will appreciate that the conception on which my disclosure is based may readily be utilized as a basis for the designing of other structures for carrying out the several purposes of my invention. It is important, therefore, that the claims to be granted me shall be of suflicient breadth to prevent the appropriation of my invention by those skilled in the art,

Referring now to the drawings Fig. 1 is a side elevation showing the preferred form of my novel lift truck as it would appear when the elevating platform is in lowered position, and also showing a raised position of thel platform in broken lines.

Fig. 2 is a cross-sectional view taken on the linev Fig. 3 is a longitudinal sectional view taken on the line 3-3 of Fig. 2,

Fig. 4 is a view similar to Fig. 3, but showing 3 the parts as they would appear when the elevating platform is in raised position.

Fig. 5 is a sectional plan view of the same, taken on the line 5 5 of Fig. 3.

In the drawing, my invention is shown as ernbodied in a lift truck having a lifting head I0, and a rearwardly disposed elevating platform II connected for lifting and lowering movement relatively to the lifting head. As is customary in trucks of this general class, the lifting head i is carried upon a wheel I2 that is mounted in a steering unit IS` pivoted in the lifting head,.there by permitting the operator to steer the truck through a handle H on the steering unit'. The wheel I2 serves as the front wheel of the truck, and preferably is driven by a suitable drive means in the unit S. A battery B thatis mounted on the lifting head I9 rearwardly of the unit S serves as a source of power, and suitable controlmeans C is located upon the handle H in a position convenient to the operator.

The elevating platform II may take any form suitable for receiving the skids or pallets with which it is tobe used, and preferably is bifurcated to provide forks adapted toenter oppositeI sides of pallets having a central'partition. 'Ihe platform II is sufficiently thin to permit it to por-tion of the platform II. The rear wheels I4- are adapted toisupportthe rear end of the platform I-I through their mountings which are in the form of swingable links, I5 pivotcd within the platform by transverse pins IVG. The rear wheels I4 and the links I5 are so constructed that4 they may be withdrawn almost completely within. the platform` I I-, thussupporting theplatform in a very low position andofferng no obstruction to their entry into a pallet, while also permitting the links I5 to be. projected as shown inFig. l to lift and support the rear endof. the platform and a` pallet thereon` This lifting action of the links I5 is produced through forwardly extending tensionrods I1 connected to the links and operated by means to be described hereinafter.

As in existing trucks of this class, thelelevating platform II is guided and restrained to occupy parallel positions as it is moved to different levels relatively to the lifting head I0, andV connecting mechanism for this purpose is accommodated in standards at the rear end of thelifting head and at the front end of the elevating platform, respectively. In. my improved lift truck, however, I construct the standards andtheir' related mechanisms in a particular manner wherebythetruck hasnovel features that wereV not heretofore possessedy by trucks of the class described.

Thus, I provide thelifting head II)` with' a vertical standard, indicated generally as I8, that is located within a complementary vertical standard, indicated generally as I9, on the front end of the elevating platform II.. The lifting head.

frame upon which the standard IB is formed comprises a pair of rearwardly extending side frame members 2U at the undersidel of the lifting head t0, these side frame members being joined by a transverse anglemember4 2l. beneath the battery B. The side frame members 20 are standard extended rearwardly and then vertically upward to provide parallel vertical plates 22 that form the opposite sides of the standard I8. The side plates 22 are laterally braced by a U-shaped vertical plate 23 that is welded to the front edges of the side plates 22 just rearwardly of the battery B, and that has a horizontal bottom flange 24 welded to the upper surface ofthe. transverse angle member 2I. The vertical side plates 22 serve as roller brackets and are provided adjacent their upper ends with a pair of outwardly extending. stubshafts 25 carrying rollers 26, and adjacent their lower ends with a pair of outwardly ex-tending stub shaftsZ'I carrying rollers 28. Provision is also made of outwardly extending stub shafts29. carrying intermediate rollers 30 closely adjacent the lower rollers 28 for a purpose that will appear.

Allnofthe rollers 26, 28 and 30 serve as followers in a track means that preferably takes the form of a pair of inwardly facing vertical channel members 3l that constitute the opposite sides` of the .complementary standard I9 onA theelevating platform II. The channel members 3I- are attached to and laterally braced by a' transversevertical plate 32 that is integrally attachedtothe front end of the elevating platform II, and are further braced at their upper ends by ahorizontal top plate 33. It will therefore be observed that the'elevating platforml I.I wilLbe restrainedto parallel positions at all stages of its` movement with respect to the lifting head ID. It will valso be observed that thelifting and lowering movements of the elevatingplatform willhaveno horizontal. component, and the lifting` head1 I8V will remain. compactly arranged Within the standard I8 at all-times. lu1ther,.ec centric warping stresses such as mightl resultl fromA unbalancedloading of. the platform. II.,.orv from other causes, willbetaken by engagement of the vertical channel .membersil withthevertical side plates 22or with theendsof the stubfshafts, therebyv eliminating any necessity for links or other cross connections to maintain the platfbrm. II in proper alignment with the lifting head. I0;

In order that the rear end. of the elevating platform II shall undergo lifting and' lowering movement upon lthe rear wheels I4 simultaneously with lifting and. lowering movement. ofi the front end of the platform, the front. ends of the tension rods II are provided with clevises 35 that are pivotally. connected to the lower ends. of a pair of levers 35 located within the standards I8, I9 just inwardly of the vertical side plates lf2.` The tension rods I'I may, if desired, have turnbuckles 36 interposed therein (Fig. l) in order to facilitate adjustment of. thev rear wheel links I5; Each of the levers 35' is mounted at an inr termediate',point'thereof upon a pivot pin 3T supported by brackets 33 that are attached to the front end ofi the platform I.I through. the trans Verse plate 32.. The upper. ends of the levers 35 arevprovided with cam followers in the form of. rollers 39 engaged with inclined cams 40, that are fixed relatively to thelifting head I0. The cams 40 preferably are mounted upon a transverse member 4I that isV attached at itsv ends to the inner surfaces of the vertical side plates 22, thus forming a part of the lifting head standard I8 and further increasing the rigidity of said standard. It will therefore be noted'that this arrangement eliminates any necessity for taking horizontal components of movement of the pivot shafts 31 into account, 'sinceI thev pivot. shafts; move4 only' in a vertical direction* relatively' tothe cams 40.

In order to take full advantage of the compactness that is permitted by the rectilinear movement of the standards relatively to each other, the

transverse plate 32 of the standard I9 is formed with apertures 42 that allow the upper ends of the levers and the rollers 39 their full range of movement, while permitting the transverse plate to be located farther forwardly than would otherwise be possible.

As a means for lifting the elevating platform I I, a hydraulic ram 43 is centrally located in a vertical position within the standards I8, I9. The lower end of the ram 43 is mounted upon the lifting head I0 by a cross-pin 44 received in apertured brackets attached to the transverse frame member 2|, and the upper end of the ram is attached to the standard I9 on the front end of the platform I I by a cross-pin 46 held in apertured brackets 4l secured to an upper portion of the vertical plate 32. The ram 43 thereby exerts a `direct lifting force that is at all times aligned with the direction of lifting movement of the platform, and the cross-pins 44, 46 undergo no pivotal movement other than may be required to accommodate minute irregularities in the relative movement of the standards I8 and I9.

At such times as there may be little or no load upon the elevating platform I I, it may be necessary that a downward force be exerted upon the platform in order to assure its downward movement when such movement is desired. For this purpose, I provide a pair of coil springs 46 that exert a certain downward force upon the standard I9 on the elevating platform at all times. As shown in Fig. 2, the lower ends of the springs 48 are provided with hooks anchored to opposite ends of the lower cross-pin 44 by apertured yokes 49. The upper ends of the springs 48 are attached to threaded rods 50 adjustably held in apertures in opposite ends of the upper cross-pin 46 by nuts 5I. Thus, it will be seen that the force of the springs 48, as well as the force of the ram 43, is exerted in a direction that is aligned with movement of the elevating platform II, and neither the springs nor the ram can produce any oblique force that would tend to bind movement of the parts, or to interfere in any way with the operation of the platform. Inasmuch as the cross-pin 46 is located above the transverse member 4I, this member is, of course, apertured in order to permit free operation of the ram 43 and the springs 48. Further, because of the fact that the ram 43 is not required to undergo any substantial swinging movement, it may be supplied with fluid under pressure through a relatively rigid conduit 52, this conduit being connected to a suitable pressure source, as will be understood by those skilled in the art.

The operation of connecting the elevating platform to the lifting head in the process of assembly may be very readily accomplished by passing the elevating platform standard I9 vertically downward over the lifting head standard I8 so that the channel members 3! receive the rollers 26, 28 and 3D. At this time the transverse member 4I will not have been assembled with the standard I8, and the levers 35 and their brackets 38 which are mounted in the standard I9 may therefore pass freely downward within the standard I8. Otherwise, however, the assembly of the parts may be substantially complete, and it will only be necessary to install the transverse member 4I and to connect the ram 43 and the springs 48 properly in order to complete the truck.

It is believed that the operation and the advantages of my novel lift truck will be apparent from the foregoing description. It may be stated briefly, however, that the arrangement of the rollers 26, 28 and 30, within the channel members 3I, provides a vertical rectilinear movement of the elevating platform I I, this movement having no horizontal or other waste components of movement. Thus, the standard I8 may be located entirely within the standard I9, so as to occupy a minimum of space longitudinally of the truck and permitting a truck of a given load capacity to be made shorter than was heretofore possible in trucks of this class. Further, the operating forces exerted upon the platform are in a vertical direction resulting in improved efficiency of force application. Movement of the elevating platform II relatively to the lifting head I0 is attended by corresponding movements of the rear end of the platform because of the action of the levers 35 that is transmitted to the rear wheel links I5. Here again, the cams 49 which operate the levers 35 move only in a rectilinear direction with respect to the pivots 31 of the levers.

The relatively large spacing of the rollers 26 vertically above the rollers 28 is a factor in maintaining the platform II rigidly in parallel positions as it is moved relatively to the lifting head I0. When the elevating platform II is in raised position, as indicated in dotted lines in Fig. 1, the lower rollers 28 will, however, be located closely adjacent the lower ends of the channel members 3 I, and the intermediate pair of rollers 30 will be of particular value at that time to insure that the standards I8 and I9 will be maintained securely assembled with each other.

I now claim:

In a truck of the class described, a lifting' head, an elevating platform, a pair of vertical rectilinear channel members on the front end of said elevating platform, roller brackets on said lifting head extending between said channel members, rollers on said roller brackets engaged in said channel members whereby to guide and restrain the front end of said elevating platform for vertical rectilinear lifting and lowering movement of said elevating platform relatively to said lifting head, a cam xed on said lifting head between said channel members, a lever mounted on and movable bodily with said elevating platform relatively to said lifting head, said lever being engaged with said cam between said channel members and swung thereby when said lever is moved bodily with said elevating platform relatively to said lifting head, means supporting said elevating platform rearwardly of said channel members for lifting and lowering movement, and means whereby said lever actuates said platform supporting means to lift and lower said elevating platform simultaneously with rectilinear movement of said platform relatively to said lifting head.

2. In a truck of the class described, a lifting head, an elevating platform, a pair of vertical rectilinear channel members on the front end of said elevating platform, a pair of vertical roller brackets on opposite sides of said lifting head between said pair of channel members, rollers on said roller brackets engaged in said channel members whereby to guide and restrain the front end of said elevating platform for vertical rectilinear lifting and lowering movement of said elevating platform relatively to said lifting head. said vertical channel members being open at their lower ends whereby to receive said rollers during assembly of said elevating platform withsaid lifting head, a cam fixed to andA between said brackets, a lever mounted on and movable bodily with said elevating platform relatively to said lifting head,k said lever being engaged with said cam between said brackets and swung thereby when said lever is moved bodily with said elevating platform relatively to said lifting head, means supporting said elevating platform rearwardly of said pair of channel members for lifting and lowering movement, and means whereby said lever actuates said platform supporting means to lift and lower said elevating platform simultaneously with rectilinear movement of said elevating platform relatively to said lifting head.

3. In a truck of the class described, a lifting head, an elevating platform, a pair of vertical channel members on the front end of said elevating platform, a pair of vertical roller brackets on sa-id lifting head between said channel members, rollers on said roller brackets engaged in said channel members whereby to guide and restrain the front end of said elevating platform for vertical lifting and lowering movement of said elevating platform relatively to said lifting head, a ram for lifting said elevating platform relatively to said lifting head, means mounting said ram in a vertical position between said roller brackets whereby the force exerted by said ram will at all times be aligned with the vertical movement of said elevating platform relatively to said lifting head, a transverse member xed between said roller brackets, a, cam fixed on said transverse member between said roller brackets, a lever mounted on andI movable bodily with said elevating platform relatively to said lifting head, said lever being engaged with said cam between said roller brackets and swung thereby when said lever ismoved bodily with said elevating platform relatively to` said lifting head, means supporting. said elevating platform rearwardly of said channel members for lifting and lowering movement, and means whereby said lever actuates said platform supporting means to lift and lower said elevating platform simultaneously with vertical movement of said platform relatively to said lifting head.

4. In a truck of the class described, a lifting head,v an elevating platform, a pair of vertical uprights on the front end of said elevating platform, a pair of vertical uprights on said lifting head, rollers mounting the vertical uprights of said elevating platform for vertical movement relatively to the vertical uprights of said lifting head and guiding the front end of said elevating platform for vertical rectilinear lifting and lowering movement relatively to said lifting head, a cam fixed relatively to said lifting head between its vertical uprights, a lever pivotally mounted on and movable bodily with said elevating platform relatively to said lifting head, said cam engaging said lever between said uprights and swinging said lever relatively to said elevating platform when said lever moves bodily upwardly with said elevating platform relatively to said lifting head, means supporting said elevating platform rearwardly of its uprights for lifting andv lowering movement, and means whereby said lever actuates said platform supporting means to lift and lower said elevating platform simultane-V ously with rectilinear movement of said platform relatively to said lifting head.

5. In a truck of the class described, a lifting head, an elevating platform, a pair of vertical uprights on the front end of said elevating platform, a pair of vertical uprights on said lifting head, rollers mounting the vertical uprights of said elevating platform for vertical movement relatively to the vertical uprights of said lifting head and guiding the front end of said elevating platform for vertical rectilinear lifting and lowering movement relatively to said lifting head, a ram bearing between said lifting head and said elevating platform for lifting said platform relatively to said lifting head, a cam fixed relatively to said lifting head between its vertical uprights. a lever, pivot means mounting said lever medially of its ends on said elevating platform for move-v ment bodily with said platform, said cam engaging oneV endv of sa-id lever and swinging said level'- on its pivot means when said lever moves with said elevating platform relatively to Said lifting head, means supporting said elevating platform rearwardly of its uprights for lifting and lowering movement, and means whereby the endof said lever opposed to said one end actuates said platform supporting means to lift and lower said elevating platform simultaneously with rectilinear movement of said platform relatively to said lifting head.

6. In a truck of the class described, a lifting head, an elevating platform, a pair of vertical uprights on the front end of said elevating platform,v a pair of vertical uprights on said lifting head, rollers mounting the vertical uprights of. said elevating platform for vertical movement relatively to the vertical uprights of said lifting head and guiding the front end of said. elevating platform for vertical rectilinear lifting and lowering movement relatively to` said lifting hea-d,y a ram bearing between said lifting head and elevating platform for lifting said platform relatively to said lifting head, a cam fixed on said lifting head between said vertical uprights, a lever, pivot means mounting saidlever onv said elevating platform for movement bodily with said platform relatively to-said lifting head, a part of said lever engaging said cam between said uprights and coacting with said cam to, swing said lever on its pivot means as said ram lifts saidv elevating platforml relatively to said lifting head, means supporting said elevating platform rearwardly of said uprights for lifting and lowering movement, andv means whereby said lever actuates said platform supporting means to lift and lower said elevatingA platformsimultaneously with rectilinear movement of said platform relatively to said lifting head.

. HERBERT J. FRAMHEIN.

References Cited in the le of this patent UNITED STATES PATENTS Number Name Date 2,359,493 Schreck Oct. 3, 1944 2,415,090 Framhein Feb. 4, 1947 2,519,128 Framhein Aug. 15, 1950. 

